B50 doesn't hold twist like the FF materials. Wax will help.
It IS simple. So simple it's dang near impossible to explain in words. It's the concept that's important, not so much the technique which can be unique for each individual. In the most basic terms, each lay is twisted in one direction. Then when combined together twisted in the other direction simultaneously untwisting each but wrapping around each other. Again, too simple to put into words. I don't "twist" the whole string for example, just the loops. I do put about 20 turns reverse twist into the lays though, which is the critical step, BEFORE you start the second loop.
You don't need a "jig" to measure the stands either. Just lay one on the braced bow, wrap it around the nock extending an appropriate lenght back onto itself to allow for joining the loop. Leave about 2" extra for the twist factor, then stagger the stands about 1/4" each.
There's a certain knack to it you develop after a while, like most manual tasks. It's great fun at first but has become a burden for me actually after countless dozens.
I did twist up a little lenght of cordage for my dotter in the yard one spring day, from stalks off a dead hybiscus plant. I just twisted the stalks and beat the bark off the fibers rough like and went to reverse twisting. Took maybe 2 minutes while she watched, and it was admittedly ugly but she was much impressed by the strenght of it when finished. She's older now, and at 14 it takes a lot to impress a girl! LOL
Reverse twist cordage is a primitive skill perhaps unrivaled in it's role in advancing civilizaton, imho.